Bench clamps, like this one from Kreg, use the workbench to supply some clamping pressure, while V-clamps add pressure via a vacuum pump.
These devices hold workpieces securely to your benchtop during hand tool or machine operations. Many hold-downs, including Jorgensen’s Style No. 1600 hold-downs and Veritas’ Surface Clamp, install into the 3/4-in.-diameter holes found in most workbenches: Install the hold-down clamp in a hole, tighten it over the workpiece, and you’re ready to go. A more complicated but elegant hold-down solution is the V-clamp, which uses suction to holds parts firmly to the bench. Vacuum is supplied either with a vacuum pump or a special valve that turns compressed air pressure into suction.
